1. Field of the Invention
The invention concerns a drive device for a furniture part movable in a furniture carcass, comprising an ejection device lockable in a locked position for moving the movable furniture part from a closed position into an open position, wherein the ejection device is unlockable by over-pressing the movable furniture part into an over-pressing position which is behind the closed position in a closing direction, whereby the movable furniture part is movable by the ejection device in an opening direction, wherein the movable furniture part is also movable from the closed position into the open position by pulling on the movable furniture part, wherein the ejection device remains in the locked position upon opening by pulling, and a coupling device for coupling the drive device to the movable furniture part or to the furniture carcass. The invention further concerns an article of furniture having such a drive device.
2. Description of Related Art
So-called touch latch mechanisms have already been known for many years in the furniture fitting industry, in which an ejection device is unlocked by pressing against the movable furniture part which is in the closed position, whereupon the movable furniture part (for example, a drawer or a furniture flap) is ejected in the opening direction.
In simple touch latch mechanisms of a different general kind, the ejection device is disposed anywhere on the furniture carcass and ejects the movable furniture part at least during the first opening travel. There is no coupling device for coupling the drive device to the movable furniture part. Rather, there is only an abutment surface against which the movable furniture part directly or indirectly bears. If, in the case of such a drive device, instead of over-pressing the movable furniture part, the movable furniture part is simply pulled starting from the closed position, then the movable furniture part is lifted away from the abutment surface without triggering a movement in the drive device.
Conversely, in WO 2012/149587 A1, which is also of a different general kind, a coupling device remains in a coupling position upon ejection of the movable furniture part whereas, however, the locking device with the cardioid-shaped guide path is no longer in the locking position when opening the movable furniture part by pulling. Rather, there is provided an evasion passage by which the locking pin can evasively pass through the “heart” of the cardioid when opening by pulling. The locking position is therefore preserved upon opening by pulling.
In WO 2011/015663 A1, which relates to a different general kind of device, the coupling position between the drive device and the movable furniture part or furniture carcass is also maintained in the same fashion upon opening by pulling, but unlocking of the lockable ejection device is implemented both upon unlocking by over-pressing and also upon unlocking by pulling.
In comparison, WO 2009/114886 A1, disclosing a device of the general kind set forth herein, discloses a kind of overload protection device in which the ejection device remains in a locking position upon opening by pulling (see FIG. 30c). The catch fork, however, is pivoted against the force of a spring by a pin associated with the furniture carcass whereby the drive device is no longer coupled to the furniture carcass upon opening by pulling. A disadvantage with that structure is that, upon such opening by pulling, the drive device has to be unlocked upon reclosing the furniture part so that it is only after that that the pin can be coupled to the catch element again.